Texas plates don't have any stickers. The sticker is on the front windshield, so they'd have a problem getting that. The front and back plates are identical so I just take the front one off and put it in a safe place. If they take the back one, I have a spare. Plus I have vanity plates but still have the original number plates. Finally, I also use the security screws. None of this was planned for Mexico, it just kind of happened :)
I did have a cop try to get my drivers license once, but I wouldn't give it to him. He wasn't wearing any kind of badge and wouldn't show me his ID, so I told him that I'd give him mine if he gave me his first! We settled for me showing him my ID (but not touching it), he checked the expiration date and went on his way.